Direct part marking code reading with multimodal object sensing

ABSTRACT

An optical symbol reading system comprises an image sensor operative to capture an image of a target area, a color-sensing system sensitive to certain colors in the visible spectrum, an illumination system operative to produce various types of illumination based on illumination parameters, and a surface-profiling system arranged to measure distance to multiple points of at least one surface in the target area. The illumination system, the image sensor, and the color-sensing system are arranged such that emitted light from the illumination system, in accordance with a selected type of illumination, is directed towards the target area while a portion of the emitted light is reflected from any object of interest present in the target area and received by the image sensor and the color-sensing system. The type of illumination is selected based on output from the color-sensing system and the surface-profiling system.

TECHNICAL FIELD

The present disclosure generally relates to optical sensing andautomated vision and, more particularly, to reading direct part marking(DPM) codes utilizing an optical system with an image sensor.

BACKGROUND

Direct part marking (DPM) is a process that allows users to imprintinformation directly on an item instead of printing the code on a labelto be applied to that item. DPM may be used to mark objects, such ascomponent parts, subassemblies, manufactured goods, or other items, withan optically-readable code. Typical uses of DPM include markingpertinent information like serial numbers, part numbers, date codes, andmachine-readable symbols (e.g., barcodes, 2D codes). DPM markings may beapplied to an object using indenting, embossing, engraving,laser-etching, electro-chemical etching, stamping, stenciling, dotpeening, inkjet printing, or other suitable technique.

DPM readers may be incorporated into handheld devices, or they may bemounted to structures or machinery. Reader devices are ideally designedto read a variety of DPM symbol types from different surfaces of objectshaving various shapes, materials, colors, or surface finishes. Inaddition, the reading should be effective and reliable under varyinglighting conditions, and at varying reading distances and relativeorientations between the DPM reader and the surface. Furthermore, a DPMreader should preferably capture a usable image of the DPM symbol(s)quickly, which may be critical in applications using handheld readers orwhere the object and DPM reader are in relative motion. Theserequirements present a number of practical challenges for designers ofDPM readers.

For one, DPM symbols, unlike printed-label symbols, may not alwaysappear in a contrasting color relative to the symbol's background, whichis the object's surface. For instance, symbols which are etched,embossed, engraved, etc., to form raised or lowered surface features,are formed from the same material as the object's surface, and arevisible due to differences in light reflection from the DPM symbol'sraised or lowered features, and reflection from the background surfaceof the object. Depending on the lighting conditions and viewing angle ofthe DPM reader, the DPM symbols may be difficult to discern.

Conventional DPM readers may utilize an illumination source, such as anLED light to provide additional illumination when ambient light isinsufficient. However, the use of illumination introduces additionalchallenges, such as specular reflections, which may drown out the DPMsymbol or saturate DPM reader's image sensor. This problem may affectreading printed DPM symbols and textured symbols, alike. Further, theaddition of illumination may cause a loss of contrast between the lightreflected from the DPM symbol's raised or lowered features, and thesymbol's background, further exacerbating the challenges with suchapplications.

SUMMARY

One aspect of this disclosure is directed to an optical symbol readingsystem, that includes an image sensor operative to capture an image of atarget area; a color-sensing system that is distinct from the imagesensor and separately sensitive to certain colors in the visiblespectrum (the color-sensing system being operative to separately measureintensity levels of those colors); and an illumination system includinga plurality of sets of photo emitters that are operative to producevarious types of illumination based on illumination parameters.

The illumination system, the image sensor, and the color-sensing systemare arranged such that emitted light from the illumination system, inaccordance with a selected type of illumination, is directed towards thetarget area while a portion of the emitted light is reflected from anyobject of interest present in the target area and received by the imagesensor and the color-sensing system.

The optical symbol reading system further includes a surface-profilingsystem that is distinct from the image sensor, and is arranged tomeasure distance to multiple points of at least one surface in thetarget area.

In addition, control circuitry is coupled to the image sensor, thecolor-sensing system, the illumination system, and the surface-profilingsystem. The control circuitry is operative to autonomously: activate thecolor-sensing system and the surface-profiling system to measureconditions comprising at least a color measurement, and a set ofdistance measurements; process the conditions to produce a set ofassessed object characteristics representing at least color, distancefrom the optical symbol reading system, and orientation of the at leastone surface in the target area relative to the optical symbol readingsystem; determine the illumination parameters based on the set ofassessed object characteristics; activate the illumination systemaccording to the illumination parameters; capture a first image of thetarget area during activation of the illumination system, the targetarea including at least a portion of the object of interest thatincludes, a machine-readable symbol; and process the first image to readthe machine-readable symbol.

In a related aspect, an automated method for optically reading a symbolis provided. The method includes measuring certain colors of the visiblespectrum present in a target area; measuring distances andreflected-light intensity of multiple points of at least one surface inthe target area; based on the certain colors, on the distances, and onthe reflected-light intensity, producing a set of assessed indiciarepresenting at least color, orientation, and reflectance of the atleast one surface in the target area; determining the illuminationparameters based on the set of assessed indicia; providing illuminationlight to the target area in accordance with a selected type ofillumination based on illumination parameters; capturing a first imageof the target area while providing the illumination light, the targetarea including at least a portion of an object of interest thatincludes, a machine-readable symbol; and processing the first image toread the machine-readable symbol.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating an example optical symbol readingsystem according to some embodiments.

FIG. 2 is a diagram illustrating a handheld reader as one exampleimplementation of the optical symbol reading system of FIG. 1 accordingto related embodiments.

FIG. 3 is a high-level block diagram illustrating an example systemarchitecture of the optical symbol reading system of FIG. 1 according tosome embodiments.

FIG. 4 is a simplified block diagram illustrating a portion ofprocessing hardware of control circuitry of the optical symbol readingsystem of FIG. 1 according to an example embodiment.

FIG. 5 is a state diagram illustrating an example operational regime ofcontrol circuitry of the optical symbol reading system of FIG. 1according to an example embodiment.

FIGS. 6A and 6B are simplified diagrams illustrating examples ofdifferent orientations between a front face of the optical symbolreader, and a surface of an object of interest.

FIG. 7 is a simplified diagram illustrating a measurement configurationfor assessing reflectance characteristics according to an example.

FIGS. 8A and 8B are diagrams illustrating various types of reflectancecharacteristics, which are generally a function of surface finish of anobject of interest.

FIG. 9 is a data flow diagram illustrating an overview of the generationof measured conditions, assessed object characteristics, and theirrelationship, according to an example implementation.

FIG. 10 is a data-flow diagram illustrating an example implementation ofa parameter-setting phase of the state diagram of FIG. 5 .

DETAILED DESCRIPTION

The illustrations included herewith are not meant to be actual views ofany particular systems, memory device, architecture, or process, but aremerely idealized representations that are employed to describeembodiments herein. Elements and features common between figures mayretain the same numerical designation except that, for ease of followingthe description, for the most part, reference numerals begin with thenumber of the drawing on which the elements are introduced or most fullydescribed. In addition, the elements illustrated in the figures areschematic in nature, and many details regarding the physical layout andconstruction of a memory array and/or all steps necessary to access datamay not be described as they would be understood by those of ordinaryskill in the art.

As used herein, the singular forms “a,” “an,” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise.

As used herein, “or” includes any and all combinations of one or more ofthe associated listed items in both, the conjunctive and disjunctivesenses. Any intended descriptions of the “exclusive-or” relationshipwill be specifically called out.

As used herein, the term “configured” refers to a structural arrangementsuch as size, shape, material composition, physical construction,logical construction (e.g., programming, operational parameter setting)or other operative arrangement of at least one structure and at leastone apparatus facilitating the operation thereof in a defined way (e.g.,to carry out a specific function or set of functions).

As used herein, the phrases “coupled to” or “coupled with” refer tostructures operatively connected with each other, such as connectedthrough a direct connection or through an indirect connection (e.g., viaanother structure or component).

Aspects of the present disclosure are directed to an optical symbolreading system and the operation thereof. An optical symbol readingsystem in the present context means a device or set of devices thatinclude(s) an image sensor, an illumination system, and an objectsurface assessment system that includes a surface-profiling system and acolor-sensing system. FIG. 1 is a diagram illustrating an exampleoptical symbol reading system 100 according to some embodiments. Opticalsymbol reading system 100 includes image sensor 102, illumination system106, and an optical arrangement (including receiver optics 104 alignedwith image sensor 102 and transmitter optics 108 aligned withillumination system 106). In addition, optical symbol reading system 100includes color-sensing system 110, surface-profiling system 114, andcontrol circuitry 120 that is interfaced with image sensor 102,illumination system 106, color-sensing system 110, and surface-profilingsystem 114.

FIG. 2 is a diagram illustrating handheld reader 200 as one exampleimplementation of scanning system 100. Handheld reader 200 includeshousing 202, and pushbutton control 206. As depicted, handheld reader200 also includes front face 208, which include image sensor 212,illumination system 216, color-sensing system 220, surface-profilingsystem 222, and aiming system 224. Image sensor 212, illumination system216, color-sensing system 220, and surface-profiling system 222 in thisexample are implementations of image sensor 102, illumination system106, color-sensing system 110, and surface-profiling system 114. Aimingsystem 224 may include a set of one or more laser designators, or alaser pattern projector (e.g., in the form of a “+” a rectangle, or thelike) in the visible spectrum.

As depicted, illumination system 216 may include photo emitters on frontface 208. In a related embodiment (not shown), multiple groups of photoemitters include one group situated relatively closer to image sensor102 than the other group, such that light transmitted by each of twogroups of emitters, which is directly reflected from the target area, isoriented at different angles relative to image sensor 212.

According to other embodiments (not shown), a reader may be mounted to astationary or mobile structure. Examples of mounting locations forvarious scanning applications include vehicles, doorways, ramps,conveyors, buildings, robots, or the like. In mounted implementations,the various transducers as located on front face 208 of thehandheld-device implementation illustrated in FIG. 2 may have their ownrespective housings, which may be separate from the image processingsystem hardware.

Referring again to FIG. 1 , image sensor 102 according to variousembodiments may include an array of photosensing elements. Examples ofphotosensing elements include complementary metal-oxide semiconductor(CMOS) sensors, charge-coupled devices (CCDs), light-emitting diodes(LEDs)), photoresistors, quantum dot photoconductors or photodiodes, andthe like. Image sensor 102 may be constructed using any suitabletechnology, whether known or arising in the future. Without limitation,some other examples include high-dynamic-range (HDR) sensors,hyperspectral sensors, polarized sensors, or the like. An array ofphotosensing elements may include a 2-dimensional array (e.g., a matrixof cells of photosensing elements).

Illumination system 106 according to some embodiments includes a diverseset of photo emitters that includes at least two different types ofphoto emitters. As depicted in the example of FIG. 1 , three photoemitters, 106A, 106B, and 106C are arranged to illuminate target area130, which may contain an object of interest 132, which may include oneor more DPM or other symbols. The different types of photo emitters106A, 106B, and 106C may be adapted to emit light in correspondinglydifferent wavelengths or combinations of wavelengths. For example, photoemitter 106A may emit red light, whereas photo emitter 106B may emitblue light. Photo emitter 106C may combine multiple wavelengths amongthe red, green, and blue spectra to produce a white light. The variouswavelengths of illumination may be achieved using color-specificemitters, color filters, colored reflectors, or a combination of anysuch techniques.

Each photo emitter 106A, 106B, 106C may be a group of similar individualdevices that work in unison, or may be an individual device. Thedifferent types of photo emitters of illumination system 106 may beselectively activated by control circuitry 120 to illuminate target area130 with one or more wavelengths of the spectrum. Thus, in the exampledepicted, photo emitter 106A may be separately controlled from photoemitters 106B and 106C. In a related embodiment, each photo emitter106A, 106B, 106C may include two or more different types of individualphoto emitter devices to produce a plurality of wavelengths that may beactivated together.

Transmitter optics 108A-108C (generally referred to as optics 108),which may be formed from glass, thermoplastic, or other suitabletransparent material, are arranged to pass or focus the emitted light,to illuminate target area 130. Transmitter optics 108 may be implementedas a window, a transparent cover, an objective lens, a microlens array,or other suitable optical arrangement. The emitted and focusedillumination reflects from target area 130 and any object of interest132. Receiver optics 104 may be formed from glass, thermoplastic, orother suitable transparent material, and arranged to pass or focus aportion of the light reflected from target area 130 or object ofinterest 132 onto image sensor 102. Receiver optics 104 may beimplemented as a window, a transparent cover, an objective lens, amicrolens array, autofocus actuator system, tunable lens, liquid lens, acombination of two or more of the foregoing, or other suitable opticalarrangement. In related embodiments, receiver optics 104 implement anautofocus system.

According to various embodiments, photo emitters of illumination system106 may be arranged to produce direct illumination, diffuseillumination, or a combination of direct and diffuse illumination. Inthe case of direct illumination, a photo emitter may be arranged to emitlight which passes through a transparent, low-dispersion opticalcomponent 108 (e.g., window or lens). In the case of diffuseillumination, a photo emitter may be may be arranged to emit light whichpasses through a textured optical component 108 that disperses suchlight.

In one implementation, an optical component 108 is shared among two ormore of the emitters 106A, 106B, 106C of illumination system 106. Forinstance, the optical component may be a window with a textured(diffusing) portion and a non-textured portion, with certain emitterspositioned such that their emitted illumination passes through eitherthe diffusing, or non-diffusing, portion of the window.

In one example embodiment, illumination system 106 includes one or morebright white emitter(s) arranged to provide direct illumination througha non-dispersive portion of optical component 108, one or more redemitter(s) arranged to provide diffuse illumination by passing the lightthrough a textured portion of an optical component 108, and one or moreblue emitters arranged to reflect emitted light from a blue surfaceinternal to illumination system 106, and that reflected blue lightpasses through a textured portion of an optical component 108.

In related embodiments, certain photo emitters of illumination system106 may be situated in a spaced relationship with one another. Forinstance, photo emitters of the same type may be positioned on oppositeends of the face of optical symbol reading system 100. One such exampleof spacing between photo emitters is illustrated in FIG. 2 , wheregroups of photo emitters of illumination system 216 are spaced apart.

Color-sensing system 110 includes a set of photosensors arranged todetect various wavelengths of light (e.g., red, green, blue, andinfrared), and the intensities of those wavelengths, which are reflectedfrom target area 130. The information obtained by color-sensing system110 is indicative of the color and shade prevalent in target area 130.As described in greater detail below, such color and shade informationmay be used to autonomously determine a suitable operational setting forillumination system 106. As an example of one implementation,color-sensing system 110 may include digital color sensor model no.BH1749NUC, manufactured by ROHM Semiconductor of Kyoto, Japan.

In a related embodiment, field-of-view (FoV) limiter 112 is provided infront of the set of photosensors of color-sensing system 110 to reduceits FoV. For instance, the FoV of color-sensing system 110 may bereduced by FoV limiter 112 to a small fraction (e.g., <10%) of the FoVof image sensor 102, and positioned in the center of the FoV of imagesensor 102. In a related example, FoV limiter 112 limits the FoV ofcolor-sensing system 110 to approximate the FoV of an aiming system 224.Accordingly, color-sensing system 110 avoids exposure to extraneoussources or reflections of illumination which are outside of the area ofgreatest interest within target area 130.

Surface-profiling system 114 includes a 3D measurement system thatmeasures distance to points in target area 130, including distance toany object of interest 132 in the target area. In various embodiments,surface-profiling system 114 includes a multipoint 3D measurement systemthat is arranged to measure distance to multiple points within targetarea 130. In some example implementations, surface-profiling system 114includes a multi-zone time-of-flight (ToF) sensor that comprises aranging illuminator which is arranged to illuminate a portion of targetarea 130, and a receiving array of single-photon avalanche diodes (SPAD)that is sensitive to the ranging illumination, and which is arranged todetect reflected light from the illuminated portion of target area 130and ascertain distances to a plurality of points in in the illuminatedportion of target area 130 based on the relative ToFs to and from thosepoints. An example of a suitable multi-zone ToF sensor is model no.VL53L5CX, manufactured by ST Microelectronics of Geneva, Switzerland.

Other implementations of surface-profiling system 114 according tovarious embodiments may include a stereoscopic camera system with aninfrared texture projector and depth-measurement capability, such as theRealSense™ series of 3D cameras manufactured by Intel Corporation ofSanta Clara, California. Still other measurement technologies that maybe suitable for surface-profiling system 114 are contemplated. Forexample, scanning light-detection-and-ranging (LiDAR) technology mayalso provide suitable distance-to-object measurements.

In the diagram of FIG. 1 , no optical components associated withcolor-sensing system 110 or surface-profiling system 114 areillustrated, though such optical components (e.g., lenses, filters,windows) may be provided in certain embodiments.

Control circuitry 120 coordinates the operation of the variouscomponents and subsystems of optical symbol reading system 100. Suchoperations include responding to activation of system 100 to initiatereading of a DPM or other symbol, using color-sensing system 110 andsurface-profiling system 114 to assess the object-related conditions ofobject of interest 132. Also, operations controlled by control circuitry120 include selecting an operating mode of illumination system 106 thatis suited to the assessed conditions of target area 130 and the assessedconditions and orientation of the surface of object of interest 132.Control circuitry 120 is further operative to activate and read imagesensor 102 and, in implementations using an autofocus system, set thefocus.

FIG. 3 is a high-level block diagram illustrating an example systemarchitecture of optical symbol reading system 100, with variouscomponents of control circuitry 120 shown. Control circuitry 120includes processing hardware 302 operatively coupled to sensor interface304, display or indicators 310, communications circuitry 314, andactuator interface 306. Processing hardware 302 includes one or moreprocessor circuits that execute software or firmware instructions 303,with the latter being stored in a non-transitory machine-readable mediumsuch as a read-only memory, flash memory, random-access memory, or thelike.

Control circuitry 120 includes various engines, each of which isconfigured to carry out a function or set of functions, as detailedbelow. The term “engine” as used herein means a tangible device,component, or arrangement of components implemented using hardware, suchas by an application specific integrated circuit (ASIC) orfield-programmable gate array (FPGA), Complex Programmable Logic Device(CPLD), for example, or as a combination of hardware and software, suchas by a processor-based computing platform and a set of programinstructions that transform the computing platform into aspecial-purpose device to implement the particular functionality. Anengine may also be implemented as a combination of the two, with certainfunctions facilitated by hardware alone, and other functions facilitatedby a combination of hardware and software.

In an example, the software may reside in executable or non-executableform on a tangible machine-readable storage medium. Software residing innon-executable form may be compiled, translated, or otherwise convertedto an executable form prior to, or during, runtime. In an example, thesoftware, when executed by the underlying hardware of the engine, causesthe hardware to perform the specified operations. Accordingly, an engineis specifically configured (e.g., hardwired), or temporarily configured(e.g., programmed) to operate in a specified manner or to perform partor all of any operations described herein in connection with thatengine.

In examples in which engines are temporarily configured, each of theengines may be instantiated at different moments in time. For example,where the engines comprise a general-purpose hardware processor coreconfigured using software; the general-purpose hardware processor coremay be configured as respective different engines at different times.Software may accordingly configure a hardware processor core, forexample, to constitute a particular engine at one instance of time andto constitute a different engine at a different instance of time.

In certain implementations, at least a portion, and in some cases, all,of an engine may be executed on the processor(s) of one or morecomputers that execute an operating system, system programs, andapplication programs, while also implementing the engine usingmultitasking, multithreading, distributed (e.g., cluster, peer-peer,cloud, etc.) processing where appropriate, or other such techniques.Accordingly, each engine may be realized in a variety of suitableconfigurations, and should generally not be limited to any particularimplementation exemplified herein, unless such limitations are expresslycalled out.

In addition, an engine may itself be composed of more than onesub-engines, each of which may be regarded as an engine in its ownright. Moreover, in the embodiments described herein, each of thevarious engines corresponds to a defined functionality; however, itshould be understood that in other contemplated embodiments, eachfunctionality may be distributed to more than one engine. Likewise, inother contemplated embodiments, multiple defined functionalities may beimplemented by a single engine that performs those multiple functions,possibly alongside other functions, or distributed differently among aset of engines than specifically illustrated in the examples herein.

Sensor interface 304 includes circuitry facilitating the exchange ofdata between processing hardware 302 various sensor devices, such asinput devices 308, image sensor 102, color-sensing system 110, andsurface-profiling system 114. In various examples, input devices 308 mayinclude user-operable controls, such as pushbuttons, a trigger, keypad,or touchscreen, and the like, as well as additional sensors, anaccelerometer, thermometer, humidity sensor, precipitation sensor,smoke/particulate sensor etc.

In some examples, sensor interface 304 includes data buffers, videodecoders, video encoders, address and data bus interfaces, serial datareceiver/transmitter circuitry, analog-to-digital (A/D) convertercircuitry, and the like. In simpler embodiments, sensor interface 304may comprise address and data busses, or a serial interface such as CAN,I²C, or the like, over which the sensor devices communicate. The datacommunications portions of sensor interface 304 may facilitate wired orwireless communication. Sensor interface 304 is operative to pass data(e.g., switch state(s), touchscreen input, activated pixels, images,video frames, color-sensing system output, data from which to performsurface profiling) from their original format as output by image sensor102, input devices 308, color-sensing system 110, or surface-profilingsystem 114, to processing hardware 302 in a suitable data format to beread by processing hardware 302.

In a related example, sensor interface 304 may additionally beconfigured to pass information from processing hardware 302 to imagesensor 102. This upstream information may include configuration commandssuch as sensor gain settings, frame rate, exposure control,activation/deactivation commands, focus setting, etc.

In some embodiments, sensor interface 304 may be integrated as part of adigital signal processor (DSP) device or microcontroller device. Inother embodiments, sensor interface 304 may be integrated as part ofimage sensor 102. In a related embodiment, sensor interface 304 may haveportions distributed among image sensor 102, color-sensing system 110,or surface-profiling system 114.

Actuator interface 306 includes circuitry to control the operation ofindividual ones, or groups, of the photo emitters of illumination system106. Actuator interface 306 may include current regulator circuitry,switching circuitry, or the like.

Display or indicators 310 include devices such as a liquid-crystaldisplay (LCD), LED indicators, speaker or buzzer, and other suitableoutput devices.

Communications circuitry 314 includes wired or wireless communicationsfacilities that provide input and output to and from processing hardware302. Communication circuitry may include one or more of the followingtypes of communication circuits: universal serial bus (USB), CAN, I²C,SPI, UART, I³C, Ethernet, personal-area network such as Bluetoothaccording to an IEEE 802.15 standard, Wi-Fi according to an IEEE 802.11standard, or the like.

FIG. 4 is a simplified block diagram illustrating a portion ofprocessing hardware 302 of control circuitry 120 according to oneexample. Processing hardware 302 includes instruction processor 410,video processor 412, and input/output (I/O) controller 414. Instructionprocessor 410 is constructed to execute software or firmwareinstructions 303, the execution of which causes instruction processor410 to implement engines to carry out the overall functionality ofoptical symbol reading system 100 in conjunction with the othercomponents of control circuitry 120, image sensor 102, and illuminationsystem 106 as shown in FIG. 3 . For instance, instruction processor 410may read input devices 308 and take actions in response to those inputs;instruction processor 410 may write output to display or indicators 310;and instruction processor 410 may exchange data with communicationscircuitry 314 to send and receive data to or from other devices. Inaddition, instructions 303, when executed by instruction processor 410,may cause instruction processor 410 to carry out condition measurements,condition evaluation based on the measurements, setting of operationalparameters of illumination and image capture, image capturing, imageprocessing, ranging determination (e.g., triangulation) and myriad otheroperations relating to the application of optical symbol reading system100.

Instruction processor 410 may be of any suitable architecture. As anexample, instruction processor 410 may include a central processing unit(CPU) core, RAM, non-volatile memory, memory controllers, address anddata (or shared) busses, serial communications ports such a universalsynchronous receiver/transmitter (UART), and peripheral circuitry suchas timers, event counters, A/D or D/A converters, pulse-width modulation(PWM) generator, etc.

Video processor 412 is interfaced with instruction processor 410, andimplements engines to receive captured images from image sensor 102, andto resample, crop, compress, or combine portions of images, filter,evaluate visual characteristics of the captured images, determine thelocation of captured visual elements within the image frame (such as thelocation of the aimer spot produced by an aimer transmitter (notshown)), and perform symbol reading or object detection algorithms,where applicable. In some embodiments, video processor 412 includes adigital signal processor (DSP) core having a computing architecture thatis optimized for video processing and including additional orspecialized arithmetic logic units (ALUs)—direct-memory access,fixed-point arithmetic, etc., ASIC, FPGA, CPLD, or combination thereof.

I/O controller 414 includes circuitry that facilitates addressing, datatransfer, memory access, and other interactions between instructionprocessor 410, video processor 412, and the other components of controlcircuitry 120. As examples, I/O controller 414 may include a bus orsystem interconnect controller, a serial communications hub controller,or the like.

In related embodiments, instruction processor 410 and video processor412 are integrated as a single processing device, such as a digitalsignal controller (DSC) that is configured to perform the respectivefunctionality of instruction processor 410 and video processor 412described above. Similarly, I/O controller 414 may also be integrated aspart of a DSC implementation. In other related embodiments, some portionof processing hardware 302 may be implemented with logic circuitry 416,such as an application-specific integrated circuit (ASIC), FPGA, CPLD,hardware coprocessor, or the like. Logic circuitry 416 may be utilizedto perform certain operations with greater speed or power efficiencythan can be conventionally achieved using an instruction processor, suchas image filtering, image frame combining, triangulation, or the like.

FIG. 5 is a state diagram illustrating an operational regime of controlcircuitry 120 of optical symbol reading system 100 according to anexample embodiment. The states include idle state 502, and operationalstates which include condition measurement phase 510,condition-evaluation phase 512, parameter-setting phase 514,image-capture phase 516, and result processing phase 518.

Condition-measurement phase 510 is initiated upon activation of opticalsymbol reading system 100 at 504, or as a new iteration followingresult-processing phase 518. In condition-measurement phase 510, controlcircuitry 120 reads color-sensing system 110, surface-profiling system114 and, optionally, other sensors such as image sensor 102, to measurecertain conditions affecting the image capture to follow for DPM orother symbol reading. may be represented as one or more data structurescontaining a set of measurements, including measurement(s) produced bycolor-sensing system 110, and measurements produced by surface-profilingsystem 114.

In some embodiments, color-sensing system 110 is operated in conjunctionwith illumination system 106. For instance, illumination system 106 maybe activated to produce a white light to illuminate object of interest132 while color-sensing system 110 is activated to measure the spectrumof reflected light from object of interest 132. The output ofcolor-sensing system 110 may be represented as a vector of intensitylevels at the various wavelengths to which color-sensing system 110 issensitive.

In various embodiments, as part of condition measurement phase 510,surface-profiling system 114 obtains data representing distances to aplurality of points on surface(s) in target area 130 (e.g., a distancesmap). A distances map obtained using surface-profiling system 114 may berepresented using any suitable data structure or format (e.g., depthmap, point cloud, triangular or quadrilateral wireframe, shell orboundary). In related embodiments, surface-profiling system 114 obtainsintensity level of each individual sensing element (e.g., pixel) of thesensor, to produce a reflected-intensity map from which reflectance ofobject of interest 132 may be discerned.

Condition measurement phase 510 produces measured conditions 520 as itsoutput. Measured conditions 520 may be represented as one or more datastructures built by control circuitry 120 containing the measurementsprovided by color-sensing system 110 and surface-profiling system 114.

Condition evaluation phase 512 is performed by control circuitry 120,and includes processing of measured conditions 520 to produce severalassessments of the characteristics of object of interest 132. In someembodiments, condition evaluation phase 512 includes processing ofmeasured conditions 520 to facilitate discrimination between object ofinterest 132 and background surface(s). For instance, the distances mapmay be processed to determine the outline of object of interest 132 andto discriminate the surface(s) of object of interest 132 from itsbackground.

Object-background discrimination may be achieved by executing a suitablealgorithm to process the distances map. As one example of such analgorithm, a boundary of an object of interest 132 may be detected bycomparing distances between adjacent or neighboring points or voxels,and identifying large differences in those distances that exceed adefined threshold to detect step-change locations. The boundary of theobject of interest 132 may be defined as a locus of neighboringstep-change locations around a cluster of distance measurementsindicating relatively closer distances than the distances outside ofthat cluster.

Likewise, as part of condition-evaluation phase 512, the shape andorientation of object of interest 132 may be discerned usingsurface-profiling system 114. For instance, the 3D profile of theportion of the object of interest 132 that is facing optical symbolreading system 100 may be ascertained following determination of theobject's boundary. For example, the 3D profile can be classified asplanar, faceted, curved, or mixed. In such embodiments, the 3D profile,and its orientation, are indicative of the way in which the illuminationwould be reflected by the object of interest 132 towards image sensor102.

In related embodiments, the profile and orientation of the of object ofinterest 132 are determined from the distances map. Accordingly, whenthe object of interest 132 is planar or faceted, the angle(s) of theplane(s) relative to optical symbol reading system 100 may be discernedbased on the distances map. In related embodiments, when the object ofinterest 132 has curved surface(s) facing optical symbol reading system100, a classification of the profile of the curvature (e.g., spherical,cylindrical, conical, parabolic, toroidal) may be discerned from thedistances map.

FIGS. 6A and 6B are simplified diagrams illustrating examples ofdifferent orientations between optical symbol reader front face 602(shown as a generalized depiction of front face 208 (FIG. 2 )), andsurface 604 of object of interest 132. Optical symbol reader front face602 includes the operative surfaces of image sensor 102, illuminationsystem 106, color-sensing system 114, and surface-profiling system 114.As shown in FIG. 6A, surface 604A is oriented such that illuminationbeam 606 that is emitted by illumination system 106 reflects fromsurface 604A to produce reflected beam 608A, which is not directlyincident on front face 602. Any specular component of reflected beam608A is thus directed away from reader front face 602. In FIG. 6B,surface 604B is oriented such that illumination beam 606 reflects toproduce reflected beam 608B which is directly incident on reader frontface 602.

As described in greater detail below, these different orientations ofsurface 604, in combination with call for different illuminationsettings. For instance, illumination may be selectively applied as:bright light, dim light, light of a particular color or set of one ormore wavelengths, direct or diffuse light, light emitted from selectedone or more emitter(s) positioned at different locations or distancesrelative to the image sensor, or any combination of these adjustableparameters.

In additional related embodiments, surface-profiling system 114facilitates measurement of reflectance characteristics of object ofinterest 132. In one such embodiment, surface-profiling system 114measures the intensity of reflected illumination from different pointson the surface of object of interest 132 which receive the incidentillumination at different angles of incidence. These measurements may beprocessed to compare the intensity values of reflected illumination thatis received from points on the surface of object 132 that closer to theoptical axis of surface-profiling system 114, and from points on thesurface of object 132 which are offset from the optical axis.

FIG. 7 is a simplified diagram illustrating a measurement configurationfor assessing reflectance characteristics according to an example.Surface-profiling system 114 includes ToF sensor 702, which emits ToFillumination 706 at a particular wavelength or wavelengths. The photonsof ToF illumination 706 reach, and reflect from, object surface 708. Thereflected beams are indicated at 710. In this diagram, the reflectedbeams 710 are labeled with numerals {−4, −3, −2, −1, 1, 2, 3, 4). Asillustrated, certain reflected beams that are closer to optical axis 704(e.g., {−1, 1}), and certain reflected beams 710 that are more offsetfrom the optical axis 704 (e.g., {−4, 4}), arrive at different angles ofincidence on object surface 708.

Similarities or differences in the intensity from received reflectedbeams 710 among received reflected beams that are closer (i.e.,impinging on sensors of ToF sensor 702 which are centrally situated),and those which are more offset, with respect to optical axis 704 (i.e.,impinging on sensors of ToF sensor 702 which are peripherally situated),may be correlated to corresponding reflectance characteristics of thesurface of the object 708. For example, if similar intensities aremeasured at the various distances from the optical axis 704, this isindicative that the characteristic of the reflectance is diffuse. If theintensities of measured reflected illumination vary substantially andsharply based on distance from the optical axis 704, this is indicativethat the reflectance is primarily specular. If the intensities ofmeasured reflected illumination vary gradually based on distance fromthe optical axis 704, this is indicative that the reflectance isprimarily spread.

FIGS. 8A and 8B are diagrams illustrating various types of reflectancecharacteristics, which are generally a function of surface finish ofobject of interest 132. FIG. 8A illustrates specular, spread, anddiffuse reflectance types. FIG. 8B illustrates hybrid reflectance types,including diffuse/specular, spread/specular, and diffuse/spread.According to some embodiments, these various types of reflectancecharacteristics may be assessed utilizing surface-profiling system 114during condition measurement phase 510, in which the measured conditions512 are gathered, and condition evaluation phase 512 in which thosemeasurements are processed to obtain a classification of reflectancecharacteristics of object of interest 132.

In related embodiments, the 3D profile and orientation of the facingsurface of object of interest 132 are taken into account when computingthe reflectance characteristics. For example, a correction function maybe applied to each portion of the surface of object of interest 132 thatis offset from the normal of surface-profiling system 114. Likewise, thegeometry of concave or convex surfaces may be taken into account whencomputing the reflectance characteristics.

Condition-evaluation phase 512 produces assessed object characteristics522 as its output. Assessed object characteristics 522 may include thecolor of the surface of object of interest 132, the distance to objectof interest 132, the 3D profile of the surface(s) of the object ofinterest 132, the orientation of the surface(s) of object of interest132, the reflectance characteristics of that surface(s) of the object ofinterest 132, and the outline of object of interest 132 against itsbackground. This information may be represented as one or more suitabledata structures, such as a list, table, database record, or the like.

FIG. 9 is a data flow diagram illustrating an overview of the generationof measured conditions 520, assessed object characteristics 522, andtheir relationship, according to an example implementation. These dataitems originate from color-sensing system 110 and surface profilingsystem 114. Color-sensing system 110 produces R-G-B-IR measurement 922as its output. Surface-profiling system 114 produces distances map 924,reflected-intensity map 926, and ambient light map 928. Data processingengine 902 implemented by control circuitry 120 operate on R-G-B-IRmeasurement 922, distances map 924, reflected-intensity map 926, andambient light processing 909 to produce assessed object characteristics522.

Data processing engine 902 performs color processing operation 903,distance map processing operation 905, and reflected intensityprocessing operation 907. Color processing operation 903 reads R-G-B-IRmeasurement 922, and processes this raw data to determine a predominantcolor as observed by color-sensing system 110. The predominant colordetermination may be a classification of the observed color into one ofa predefined set of color categories (e.g., black, white, gray, red,lime, blue, yellow, cyan, magenta, maroon, olive, green, purple, teal,or navy).

Distance map processing operation 905 reads distances map 924 producedby surface-profiling system 114, and produces object outline 944 (e.g.,which may be represented as a set of coordinates, or vectors, definingthe boundary of object of interest 132), a measure of distance 946 tothe object of interest 132 (which may be a scalar value representing thedistance to the center of object of interest 132), the 3D profile, orshape, 948 of the facing surface of object of interest 132 (which may bea classification into a category of surface shapes, such as planar,prismatic, spherical, parabolic, cylindrical, convex, concave, or thelike), and orientation 950 of the facing surface(s) of object ofinterest 132 (e.g., which may be represented as the angular offset ofthe normal vector of the surface of object of interest 132 from theoptical axis of surface-profiling system 114 or image sensor 102, alongthe x-z plane and the y-z plane where the z-axis is parallel to theoptical axis, and the x-y plane is perpendicular to the optical axis).

Reflected intensity processing operation 907 reads reflected-intensitymap 926, and receives a processing result of ambient light processing909. Based on this information, reflected intensity processing operation907 produces reflectance characteristic 952. Computation of reflectancecharacteristic 952 may be further based on at least some of the outputof distance map processing operation 905 (for example, the distance toobject 946, 3D profile 948, or orientation of surface(s) 950, which(individually or in combination) may be used to correct the reflectancedetermination to account for the surface(s) of object of interest 132being offset from the normal orientation to the optical axis).

Referring again to FIG. 5 , assessed object characteristics 522 are usedin parameter-setting phase 514 to set various operational parameters ofillumination and image capture for DPM symbol reading.

FIG. 10 is a data-flow diagram illustrating an example implementation ofparameter-setting phase 514, which may be carried out via processingcircuitry 120. As illustrated, parameter-setting engine 1002 executesillumination-setting operation 1003, focus-setting operation 1005, andautomatic exposure and gain control (AEGC)-setting operation 1007. Theresult of these operations is illumination configuration and imagecapture settings data set 524.

Assessed object characteristics 522 are used in various combinations toproduce each parameter setting operation 1003, 1005, 1007 as shown inthis example. For instance, illumination setting operation 1003 is basedon surface color assessment 942, object outline 944, distance 946 toobject of interest 132, 3D profile 948, orientation of the facingsurface(s) 950, and reflectance characteristic 952. Illumination settingoperation 1003 may set various parameters of illumination system 106.These include brightness setting 1011, which sets a variable lightoutput to a determined value, color setting 1013, which selects avariable color (e.g., red, blue, white, or other), diffusion setting1015, which selects whether the illumination is direct or diffuse (e.g.,based on a selection of emitter behind a diffusion filter, or behind atransparent window), and emitter location selection 1017, which selectscertain emitters of the appropriate type from among similar emitters invarious locations, such that the angle of incidence of the illuminationmay be selected.

Focus setting operation 1005 provides a control signal for setting thefocus 1019 of receiver optics 104 in those embodiments where such focusis adjustable. Focus setting operation 1005 may be based on the distanceto object 946, 3D profile 948, and orientation 950 of the object'ssurface(s) according to the example depicted. In a related example, whenthe object's facing surface is generally normal to the optical axis, asingle focus 1019 may be determined corresponding to the plane of thatsurface; but in situations where the object's surface is skewed relativeto the optical axis, or where the object's surface is curved along thedepth dimension such that different portions of the surface are atdifferent distances, focus setting operation 1005 may produce aplurality of focus settings 2019 corresponding to various depths tofacilitate rapid capture of a series of images at those different focalsettings.

AEGC-setting operation 1007 determines a suitable gain setting 1021, andexposure setting 1023, for image sensor 102 based on various objectcharacteristics, such as surface color assessment 942, distance toobject 946, orientation of surface(s) 950, and reflectancecharacteristic 952.

In related embodiments, different combinations of assessed objectcharacteristics may be taken into account according to correspondingparameter-setting criteria, for illumination setting operation 1003,focus setting operation 1005, or AEGC-setting operation 1007, than thecombinations exemplified in FIG. 10 .

To illustrate one example of parameter-setting criteria for illuminationsetting operation 1003, Table 1 below provides various modes ofillumination corresponding to assessed reflectance characteristic 952,and on 3D profile 948 and surface orientation 950, the combination ofwhich affects the directionality and direction of reflected illuminationfrom the surface(s) of object of interest 132:

TABLE 1 Reflectance Characteristic Reflection Diffuse/ Spread/ Diffuse/Direction Specular Spread Diffuse Specular Specular Spread IndirectBright Diffuse- Bright Bright Diffuse- Bright Bright Bright DirectDiffuse- Diffuse- Bright Diffuse- Diffuse- Diffuse- Moderate BrightModerate Bright Moderate Partially Diffuse- Diffuse- Bright Diffuse-Diffuse- Diffuse- Direct Bright Bright Bright Bright Bright

In Table 1, the Reflectance Characteristic corresponds to assessedreflectance characteristic 952, as illustrated in FIGS. 8A-8B. TheReflection Direction corresponds to the orientation and 3D profile ofthe facing surface of object of interest 132 based on 3D profile 948 andsurface orientation 950. Accordingly, the Direct reflection directioncorresponds to a surface shape and orientation that directs a largeportion of the reflected illumination towards optical symbol readerfront face 602, as depicted, for instance, in FIG. 6B. The Indirectreflection direction corresponds to a surface shape and orientation thatdirects a large portion of the reflected illumination away from opticalsymbol reader front face 602, as depicted, for instance, in FIG. 6A. ThePartially Direct reflection direction corresponds to a surface shape andorientation that directs a partial portion of the reflected illuminationtowards optical symbol reader front face 602. For each combination ofReflection Characteristic and Reflection Direction, an illuminationparameter is indicated.

In Table 1, the Bright illumination parameter indicates a direct(non-diffuse) illumination that produces a bright-intensity, specularreflection. A bright-intensity reflection in the present context is areflection that results from illumination with a white, high-intensitylight, or with a high-intensity light that has a color which is similarto the color of the surface of object of interest 132. TheDiffuse-Bright illumination parameter indicates a diffuse illuminationthat produces a bright, non-specular reflection. The Diffuse-Moderateillumination parameter indicates a diffuse illumination that produces amoderate-intensity, non-specular reflection. A moderate-intensityreflection is a reflection that results from illumination with areduced-intensity white light, or a light of a different color than thecolor of the surface of object of interest 132.

Turning again to FIG. 5 , image capture phase 516 includes operation ofimage sensor 102 and illumination system 106 according to illuminationconfiguration and image capture settings 524, to capture an image ofobject of interest 132. Accordingly, illumination is provided based onbrightness 1011, color 1013, diffusion 1015, and emitter selections1017. Furthermore, receiver optics 104 may be dynamically focused basedon focus setting 1005, and AEGC setting 1007 of image sensor 102 may beset to facilitate image capture containing a DPM or other symbol to beread.

In image capture phase 516, image sensor 102 is used to capture an imagecontaining a DPM or other symbol while the selected illumination mode isactivated. In some embodiments, image-capture phase 516 may be performediteratively with parameter setting phase 514, such that capturedimage(s) 526 may be analyzed for clarity, contrast, line quality, orother measure relating to symbol readability, to further adjustillumination configuration and image capture settings data set 524 ifnecessary.

In result processing phase 518, captured image(s) 526 are processed toread any DPM or other machine-readable symbol or characters to produceoutput 528 (e.g., representing the interpretation of the DPM or othersymbol). Result processing phase 518 may be performed based on one ormore decoding libraries containing one or more algorithms or criteriafor performing image processing of captured images 526 to identify orevaluate the DPM or other symbol on object of interest 132.

In some related embodiments, assessed object characteristics 522 may befurther utilized as criteria for selecting certain algorithms orparameters of the one or more decoding libraries. For instance, certaincolor and reflectance combinations, as represented in assessed objectcharacteristics 522 may be correlated with certain decoding libraryalgorithms or parameters, the selection of which can speed up, orimprove the accuracy, of decoding of the DPM or other symbol in resultprocessing phase 518.

The resulting output 528, may be communicated to a receiving device viacommunications circuitry 314, or presented to a user via display orindicators 310, for example. The state sequence may iterate to conditionmeasurement phase 510.

While the disclosure is susceptible to various modifications andalternative forms, specific embodiments have been shown by way ofexample in the drawings and have been described in detail herein.However, the disclosure is not limited to the particular formsdisclosed. Rather, the disclosure is to cover all modifications,equivalents, and alternatives falling within the scope of the followingappended claims and their legal equivalents.

ADDITIONAL NOTES AND EXAMPLES

Example 1 is an optical symbol reading system, comprising: an imagesensor operative to capture an image of a target area; a color-sensingsystem that is distinct from the image sensor and separately sensitiveto certain colors in the visible spectrum, the color-sensing systembeing operative to separately measure intensity levels of those colors;an illumination system including a plurality of sets of photo emittersthat are operative to produce various types of illumination based onillumination parameters, wherein the illumination system, the imagesensor, and the color-sensing system are arranged such that emittedlight from the illumination system, in accordance with a selected typeof illumination, is directed towards the target area while a portion ofthe emitted light is reflected from any object of interest present inthe target area and received by the image sensor and the color-sensingsystem; a surface-profiling system that is distinct from the imagesensor, and arranged to measure distance to multiple points of at leastone surface in the target area; and control circuitry coupled to theimage sensor, the color-sensing system, the illumination system, and thesurface-profiling system, wherein the control circuitry is operative toautonomously: activate the color-sensing system and thesurface-profiling system to measure conditions comprising at least acolor measurement, and a set of distance measurements; process theconditions to produce a set of assessed object characteristicsrepresenting at least color, distance from the optical symbol readingsystem, and orientation of the at least one surface in the target arearelative to the optical symbol reading system; determine theillumination parameters based on the set of assessed objectcharacteristics; activate the illumination system according to theillumination parameters; capture a first image of the target area duringactivation of the illumination system, the target area including atleast a portion of the object of interest that includes, amachine-readable symbol; and process the first image to read themachine-readable symbol.

In Example 2, the subject matter of Example 1 includes, wherein themachine-readable symbol is a direct part marking (DPM) symbol.

In Example 3, the subject matter of Examples 1-2 includes, wherein theillumination system comprises emitters situated at different locationsrelative to the image sensor, and wherein the various types ofillumination include various illumination sources according to selectiveactivation of different ones of the emitters situated at the differentlocations.

In Example 4, the subject matter of Example 3 includes, wherein thecontrol circuitry is further operative to autonomously determine theillumination parameters to set an illumination source from among thevarious types of illumination sources, and an automatic exposure andgain control (AEGC) setting of the image sensor, based on at least theorientation of the at least one surface in the target area relative tothe optical symbol reading system.

In Example 5, the subject matter of Examples 1-4 includes, wherein thevarious types of illumination include various colors and various levelsof brightness based on the illumination parameters.

In Example 6, the subject matter of Example 5 includes, wherein theillumination system comprises emitters operative to selectively producered, blue, and white illumination based on the illumination parameters.

In Example 7, the subject matter of Examples 5-6 includes, wherein thecontrol circuitry is further operative to autonomously determine theillumination parameters to set an illumination color based on at leastthe color of the at least one surface in the target area.

In Example 8, the subject matter of Examples 1-7 includes, wherein thevarious types of illumination include various types of diffusion basedon the illumination parameters.

In Example 9, the subject matter of Example 8 includes, wherein theillumination system comprises different sets of emitters situated behinddifferent types of transparent optical components, including a clearoptical component through which direct illumination is transmitted, anda dispersive optical component through which diffuse illumination istransmitted.

In Example 10, the subject matter of Examples 8-9 includes, wherein thecontrol circuitry is further operative to autonomously determine theillumination parameters to set a diffusion type based on at least theorientation of the at least one surface in the target area relative tothe optical symbol reading system.

In Example 11, the subject matter of Example 10 includes, wherein theset of assessed object characteristics further includes a 3D shape of atthe least one surface in the target area, and wherein the controlcircuitry is further operative to autonomously determine theillumination parameters to set a diffusion type based further on the 3Dshape.

In Example 12, the subject matter of Examples 1-11 includes, wherein theimage sensor is situated behind receiver optics that include a focusinglens, and wherein the control circuitry is further operative toautonomously determine a focus setting for the focusing lens based on atleast a portion of the set of assessed object characteristics includingat least the distance from the optical symbol reading system.

In Example 13, the subject matter of Examples 1-12 includes, wherein:the surface-profiling system is further arranged to measure reflectedintensity of illumination reflected from multiple points of the at leastone surface in the target area; the conditions further comprise thereflected intensity; and the set of assessed object characteristicsfurther represents reflectance of the at least one surface in the targetarea.

In Example 14, the subject matter of Example 13 includes, wherein: thevarious types of illumination include various types of diffusion basedon the illumination parameters; and the control circuitry is furtheroperative to autonomously determine the illumination parameters to set adiffusion type based on at least the reflectance of the at least onesurface in the target area.

In Example 15, the subject matter of Examples 13-14 includes, whereinthe assessed object characteristics that represent reflectance of the atleast one surface in the target area are represented as a reflectancemap, wherein the reflectance map includes intensity of reflectedillumination from different points on the at least one surface in thetarget area which receive illumination at different angles of incidence.

In Example 16, the subject matter of Examples 1-15 includes, wherein thecolor-sensing system comprises a set of photosensors arranged to detectvarious wavelengths of light and the intensities of those wavelengths,wherein the color-sensing system has a color-sensing field-of-view thatis limited to a fraction of a field of view of the image sensor.

In Example 17, the subject matter of Examples 1-16 includes, wherein thesurface-profiling system comprises a multi-zone time-of-flight (ToF)sensor that includes a ranging illuminator and a receiving array ofphotosensors that is sensitive to the ranging illumination.

Example 18 is an automated method for optically reading a symbol, themethod comprising: measuring certain colors of the visible spectrumpresent in a target area; measuring distances and reflected-lightintensity of multiple points of at least one surface in the target area;based on the certain colors, on the distances, and on thereflected-light intensity, producing a set of assessed indiciarepresenting at least color, orientation, and reflectance of the atleast one surface in the target area; determining the illuminationparameters based on the set of assessed indicia; providing illuminationlight to the target area in accordance with a selected type ofillumination based on illumination parameters; capturing a first imageof the target area while providing the illumination light, the targetarea including at least a portion of an object of interest thatincludes, a machine-readable symbol; and processing the first image toread the machine-readable symbol.

In Example 19, the subject matter of Example 18 includes, whereinproviding illumination light to the target area includes providing aselected illumination type from among various types of illumination thatinclude various colors, various levels of brightness, and various typesof diffusion of the illumination light, based on the illuminationparameters.

In Example 20, the subject matter of Examples 18-19 includes, whereinmeasuring distances of multiple points of at least one surface in thetarget area includes measuring a time of flight (ToF) of rangingillumination to the at least one surface.

Example 21 is at least one machine-readable medium includinginstructions that, when executed by processing circuitry, cause theprocessing circuitry to perform operations to implement of any ofExamples 18-20.

Example 22 is an apparatus comprising means to implement of any ofExamples 1-20.

Example 23 is a system to implement of any of Examples 18-20.

Example 24 is a method to implement of any of Examples 1-17.

Persons of ordinary skill in the relevant arts will recognize that theinvention may comprise fewer features than illustrated in any individualembodiment described above. The embodiments described herein are notmeant to be an exhaustive presentation of the ways in which the variousfeatures of the invention may be combined. Accordingly, the embodimentsare not mutually exclusive combinations of features; rather, theinvention may comprise a combination of different individual featuresselected from different individual embodiments, as will be understood bypersons of ordinary skill in the art.

Any incorporation by reference of documents above is limited such thatno subject matter is incorporated that is contrary to the explicitdisclosure herein. Any incorporation by reference of documents above isfurther limited such that no claims that are included in the documentsare incorporated by reference into the claims of the presentApplication. The claims of any of the documents are, however,incorporated as part of the disclosure herein, unless specificallyexcluded. Any incorporation by reference of documents above is yetfurther limited such that any definitions provided in the documents arenot incorporated by reference herein unless expressly included herein.

For purposes of interpreting the claims for the present invention, it isexpressly intended that the provisions of 35 U.S.C. § 114(f), are not tobe invoked unless the specific terms “means for” or “step for” arerecited in a claim.

What is claimed is:
 1. An optical symbol reading system, comprising: animage sensor operative to capture an image of a target area; acolor-sensing system that is distinct from the image sensor andseparately sensitive to certain colors in the visible spectrum, thecolor-sensing system being operative to separately measure intensitylevels of those colors; an illumination system including a plurality ofsets of photo emitters that are operative to produce various types ofillumination based on illumination parameters, wherein the illuminationsystem, the image sensor, and the color-sensing system are arranged suchthat emitted light from the illumination system, in accordance with aselected type of illumination, is directed towards the target area whilea portion of the emitted light is reflected from any object of interestpresent in the target area and received by the image sensor and thecolor-sensing system; a surface-profiling system that is distinct fromthe image sensor, and arranged to measure distance to multiple points ofat least one surface in the target area; and control circuitry coupledto the image sensor, the color-sensing system, the illumination system,and the surface-profiling system, wherein the control circuitry isoperative to autonomously: activate the color-sensing system and thesurface-profiling system to measure conditions comprising at least acolor measurement, and a set of distance measurements; process theconditions to produce a set of assessed object characteristicsrepresenting at least color, distance from the optical symbol readingsystem, and orientation of the at least one surface in the target arearelative to the optical symbol reading system; determine theillumination parameters based on the set of assessed objectcharacteristics; activate the illumination system according to theillumination parameters; capture a first image of the target area duringactivation of the illumination system, the target area including atleast a portion of the object of interest that includes amachine-readable symbol; and process the first image to read themachine-readable symbol.
 2. The optical symbol reading system of claim1, wherein the machine-readable symbol is a direct part marking (DPM)symbol.
 3. The optical symbol reading system of claim 1, wherein theillumination system comprises emitters situated at different locationsrelative to the image sensor, and wherein the various types ofillumination include various illumination sources according to selectiveactivation of different ones of the emitters situated at the differentlocations.
 4. The optical symbol reading system of claim 3, wherein thecontrol circuitry is further operative to autonomously determine theillumination parameters to set an illumination source from among thevarious types of illumination sources, and an automatic exposure andgain control (AEGC) setting of the image sensor, based on at least theorientation of the at least one surface in the target area relative tothe optical symbol reading system.
 5. The optical symbol reading systemof claim 1, wherein the various types of illumination include variouscolors and various levels of brightness based on the illuminationparameters.
 6. The optical symbol reading system of claim 5, wherein theillumination system comprises emitters operative to selectively producered, blue, and white illumination based on the illumination parameters.7. The optical symbol reading system of claim 5, wherein the controlcircuitry is further operative to autonomously determine theillumination parameters to set an illumination color based on at leastthe color of the at least one surface in the target area.
 8. The opticalsymbol reading system of claim 1, wherein the various types ofillumination include various types of diffusion based on theillumination parameters.
 9. The optical symbol reading system of claim8, wherein the illumination system comprises different sets of emitterssituated behind different types of transparent optical components,including a clear optical component through which direct illumination istransmitted, and a dispersive optical component through which diffuseillumination is transmitted.
 10. The optical symbol reading system ofclaim 8, wherein the control circuitry is further operative toautonomously determine the illumination parameters to set a diffusiontype based on at least the orientation of the at least one surface inthe target area relative to the optical symbol reading system.
 11. Theoptical symbol reading system of claim 10, wherein the set of assessedobject characteristics further includes a 3D shape of at the least onesurface in the target area, and wherein the control circuitry is furtheroperative to autonomously determine the illumination parameters to set adiffusion type based further on the 3D shape.
 12. The optical symbolreading system of claim 1, wherein the image sensor is situated behindreceiver optics that include a focusing lens, and wherein the controlcircuitry is further operative to autonomously determine a focus settingfor the focusing lens based on at least a portion of the set of assessedobject characteristics including at least the distance from the opticalsymbol reading system.
 13. The optical symbol reading system of claim 1,wherein: the surface-profiling system is further arranged to measurereflected intensity of illumination reflected from multiple points ofthe at least one surface in the target area; the conditions furthercomprise the reflected intensity; and the set of assessed objectcharacteristics further represents reflectance of the at least onesurface in the target area.
 14. The optical symbol reading system ofclaim 13, wherein: the various types of illumination include varioustypes of diffusion based on the illumination parameters; and the controlcircuitry is further operative to autonomously determine theillumination parameters to set a diffusion type based on at least thereflectance of the at least one surface in the target area.
 15. Theoptical symbol reading system of claim 13, wherein the assessed objectcharacteristics that represent reflectance of the at least one surfacein the target area are represented as a reflectance map, wherein thereflectance map includes intensity of reflected illumination fromdifferent points on the at least one surface in the target area whichreceive illumination at different angles of incidence.
 16. The opticalsymbol reading system of claim 1, wherein the color-sensing systemcomprises a set of photosensors arranged to detect various wavelengthsof light and the intensities of those wavelengths, wherein thecolor-sensing system has a color-sensing field-of-view that is limitedto a fraction of a field of view of the image sensor.
 17. The opticalsymbol reading system of claim 1, wherein the surface-profiling systemcomprises a multi-zone time-of-flight (ToF) sensor that includes aranging illuminator and a receiving array of photosensors that issensitive to the ranging illumination.
 18. An automated method foroptically reading a symbol, the method comprising: measuring certaincolors of the visible spectrum present in a target area; measuringdistances and reflected-light intensity of multiple points of at leastone surface in the target area; based on the certain colors, on thedistances, and on the reflected-light intensity, producing a set ofassessed indicia representing at least color, orientation, andreflectance of the at least one surface in the target area; determiningthe illumination parameters based on the set of assessed indicia;providing illumination light to the target area in accordance with aselected type of illumination based on illumination parameters;capturing a first image of the target area while providing theillumination light, the target area including at least a portion of anobject of interest that includes a machine-readable symbol; andprocessing the first image to read the machine-readable symbol.
 19. Themethod of claim 18, wherein providing illumination light to the targetarea includes providing a selected illumination type from among varioustypes of illumination that include various colors, various levels ofbrightness, and various types of diffusion of the illumination light,based on the illumination parameters.
 20. The method of claim 18,wherein measuring distances of multiple points of at least one surfacein the target area includes measuring a time of flight (ToF) of rangingillumination to the at least one surface.